As is well known, one form of conventional compass includes a pin or the like at the distal end of one of the legs thereof which serves as a pivot point about which the other, marking leg rotates during use of the compass. The sharp pointed end of the pin of a compass presents an obvious injury hazard, and a number of approaches have been taken in providing a protective covering or shield for the sharp end, including simple thimble-like covers.
Other protective devices for this purpose are more complex, and patents of interest in this field include the following: Japanese Patent No. JP 10193877A2 to Yamazaki; U.S. Pat. No. 341,081 to Weissenborn, U.S. Pat. No. 2,718,703 to Chilcote; U.S. Pat. No. 4,616,418 to Wade, III; and U.S. Pat. No. 6,311,404 to Smith.
Briefly considering these patents, the Yamazaki patent application discloses a drawing compass having a pivotable protective cover member for concealing the tip of the pin. The Weissenborn patent discloses a compass having two sharp points. A rubber casing protector having a pair of slits is provided and the sharp points of the compass are inserted into the rubber casing, via the slits, so as to protect the points of the compass and prevent injury to a user of the compass. The Chilcote patent discloses a compass protector which includes a guard device for receiving the sharp point of the compass when the compass is not in use so as to protect the user against injury. The Wade, III patent discloses a beam compass having exchangeable parts for making drawings on a variety of surfaces. A marker carrier is adapted to receive a large marker such as a felt-tip pen while a chuck receives smaller diameter markers such as crayons or chalk. When a needle is employed, a slidable guard can be used to selectively cover the needle. The Smith patent discloses a compass assembly having a removable marking device attached to one of two legs. A second leg contains a retractable sleeve including a spring and engaging pin therein. In use, pressure applied to the second leg pushes the engaging pin through a hole in the retractable sleeve and thus anchors the compass. A sleeve is provided to encase the pointed end of the pin when the pin is not in use.